* {
    margin: 0;
    padding: 0;
}
li {
    list-style: none;
}

span {
    user-select: none;
}

.tangram {
    float: left;
}

.div1 {
    float: left;
    width: 100px;
    height: 100px;
    margin: 0 100px 0 0;
}

.square {
    position: absolute;
    top: 250px;
    left: 0;
    width: 100px;
    height: 100px;
    background: aqua;
    border: 1px solid;
    user-select: none;
    cursor: pointer;
    /* 虚线产生在内部,不占盒子大小 */
    box-sizing: border-box;
}
.triangle {
    position: absolute;
    top: 250px;
    left: 0;
    width: 100px;
    height: 100px;
    border: 1px solid;
    cursor: pointer;
    box-sizing: border-box;

    clip-path: polygon(0 0, 0% 100%, 100% 100%);
}
.parallelogram {
    position: absolute;
    top: 250px;
    left: 0;
    width: 200px;
    height: 100px;
    background: blue;
    border: 1px solid;
    cursor: pointer;
    box-sizing: border-box;

    transform: skew(-45deg);
}

.generate {
    position: absolute;
    top: 0;
    left: 200px;
    width: 200px;
    height: 180px;
    /* border: 5px solid rgb(255, 0, 0); */
    font-size: 4em;
}

.menu {
    position: fixed;
    left: 0;
    top: 0;
    padding: 5px;
    border-radius: 5px;
    background-color: #f9f9fb;
    box-shadow: 2px 2px 5px;
    visibility: hidden;
    cursor: pointer;
    z-index: 999999999;
}
